Watermain Cleaning Program


Municipal Office

395 Mulock Drive P.O. Box 328 Station Main, Newmarket, Ontario
L3Y 4X7

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Unidirectional Flushing

The Town conducts a Unidirectional Flushing (UDF) Program each year. This process is considered to be one of the best ways to preserve high water quality and maintain the reliability of the water distribution system.

This program will be performed throughout a majority of the summer, usually between May to October. Along with Town of Newmarket Operators, a contractor has been retained to assist with performing this flushing activity. 

The UDF method of cleans the watermains through a network of flushing sequences with the water being discharged from a fire hydrant. A UDF activity involves closing valves in a specific sequence to create water movement in one direction while opening specific hydrants at the end of that sequence. This technique allows for higher water flow velocities by isolating certain sections of watermains. The higher water velocity allows for better scouring of the pipes and can use up to 40% less water in the flushing process compared to conventional flushing methods. Flushing pipes at higher velocities will dislodge and remove mineral deposits, biofilm and sediment that accumulate in the watermains.

In most cases, customers will not notice any changes to their water delivery during the UDF process. However, in some instances, homes may experience a temporary slight drop in water pressure and/or discolouration in cold water. There should be no disruption in service.

Due to varying rates and directions of flow in the water distribution system, our customers may experience a slight discolouration in their water, which at times in unavoidable. Under most circumstances, you can run your faucets for a short time after the testing is completed and the water should clear at your residence. Discoloured water in itself does not pose a health hazard, however if the water does not clear up after running your tap for a few minutes please contact Customer Service at 905 895-5193.

View our uni-directional flushing graphic below for more information on how unidirectional flushing works! 




We apologize for any inconvenience this work may present and thank you for your cooperation and support.

To speak with someone about this program, please call 905-895-5193.

Watermain swabbing 

The Town of Newmarket uses a variety of industry-approved techniques - like watermain swabbing – to do a thorough cleaning of watermains that, over time, see a build-up of sediment. 

Watermain swabbing involves inserting a foam sponge – or 'swab' – into the watermain through a fire hydrant. The diameter of the swab is slightly larger than the watermain, and it is pushed along through the watermain using water pressure. As it passes through, the swab clears any sediment that has built up inside the watermain. The swab is then pushed up and released through another fire hydrant.

The Town always does its best to reduce impacts to Newmarket residents and businesses. However, during the cleaning process, some residents' usage may be impacted for a short period of time. Residents in the affected households are notified at least 24 hours in advance that watermain cleaning will be taking place on their street, and are provided with information on what to do with their water while they wait.

Learn more about the Town of Newmarket's Watermain Cleaning Program by watching the video below:


Need more information? Read the Watermain Cleaning Program Frequently Asked Questions​.

To speak with someone about this program, please call 905-895-5193.​​

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